Hairy cell leukemia (HCL) is a hematological malignancy characterized by an accumulation of abnormal B lymphocytes. It is usually classified as a sub-type of chronic lymphoid leukemia. HCL was originally described as histiocytic leukemia, malignant reticulosis, or lymphoid myelofibrosis. The disease was formally named leukemic reticuloendotheliosis and its common name is derived from the “hairy” appearance of the malignant B cells under a microscope.
It is essential to distinguish HCL from other lymphoid malignancies that can masquerade as this disease (e.g., hairy cell variant; splenic marginal zone lymphoma, chronic lymphocytic leukemia, prolymphocytic leukemia, other low grade lymphomas, and systemic mastocytosis). HCL diagnosis is currently based on a combination of methodologies including, physical examination, complete blood count (cbc), peripheral blood smears in conjunction with electron and light microscopy, flow cytometry and tartrate resistant acid phosphatase (TRAP) analysis. However, none of these tests can accurately diagnose HCL and a bone marrow biopsy is required for confirmation.
Accordingly, there is a need in the art to identify genes and proteins which may be dysregulated during the development and progression of hairy cell leukemia, and to utilize these genes and proteins as biomarkers for disease diagnosis and for monitoring disease progression and therapeutic treatment efficacy. The present invention addresses these needs.